[Below is the original script. But a few changes may have been made during the recording of this audio podcast.]

The U.S. already has high-speed trains: the Acela Express has been carrying millions of riders between Washington, D.C., New York and Boston since 2000. It zips along at 150 miles per hour for relatively short distances—just over 25 miles per hour faster than conventional counterparts.

But compare it with high-speed trains in Europe and Asia that can reach speeds over 200 miles per hour on hundreds of miles of track. The problem is: tracks in the U.S. are not designed to support high-speed travel. Plus, any new express trains might have to share those lines with slower freight traffic.

So is high speed train travel even possible in the U.S.?

Well, the Obama administration hopes to make it so, setting aside $8 billion to create 10 high-speed lines between cities in the east, Southeast, Midwest, and west coast.

But it will take a lot more money to bring the U.S. passenger rail system up to the standards of, say, the French Train a Grande Vitesse, which runs on dedicated tracks and holds the record for fastest train at 357 miles per hour.

And Amtrak has proven woefully inadequate at providing passenger rail service in its three decades of existence, requiring constant infusions of government cash and rarely keeping to schedule.

So don't expect high-speed trains to show up fast at your local station.